In housing construction, a newly installed or repaired operating sewage line of a home's waste or sewer drainage system must remain isolated from the sewage service line until the plumbing construction is inspected and certified. It is common practice within the construction industry to place an outlet end of a newly installed sewage line of the building at a juncture near an inlet to a sewage service line. At this point in construction, these two lines are not connected. Where these two lines would otherwise meet, each line is capped-off until testing and inspection is complete. Usual construction techniques often require that the juncture be buried before the tests are performed. After the testing and inspection is complete, the juncture is re-excavated and a proper connection of the two lines is made.
Various patents have been issued with respect to test or isolation valve assemblies.
Sullivan (U.S. Pat. No. 4,429,568) discloses a closure plug for pressure testing a liquid drain and vent plumbing type system. Sullivan uses a clean-out Y for access to open the plug plate assembly.
Cohen (U.S. Pat. No. 1,720,819) discloses a test T having a tapered gate which closes off a house drain pipe from a drainage system. After the test has been completed, the gate is removed from the test T and the resulting opening in the tee is closed by a cover plate.
Tagliarnio (U.S. Pat. No. 4,542,642) discloses a test tee having a plug which is a removable blocking disk. The blocking disk engages a ledge in the test tee and seals the drainage system. The disk is accessible and removable through an access means.
Roberson (U.S. Pat. No. 4,658,861) discloses a pneumatic plug inserted through a clean-out T to block off a house service line to a main sewer line.
Kennedy (U.S. Pat. No. 1,948,220) discloses a test plumbing system using a flap valve which is pivoted at an upper side of a valve seat. The flap valve is held in position by a valve adjusting rod.
Applicant believes the listed patents and known procedures taken alone or in combination neither anticipate nor render obvious the present invention. The listed references only relate to the general field of the disclosure. These citations do not constitute an admission that the references are relevant or material to the claims. These references are cited only as constituting the closest art of which the applicant is aware.